Dip stick

ABSTRACT

A dip stick assembly with a tubular body having an internal ledge of a fixed position and a cup-shaped external opened end with a closure cap adapted to close the end, the closure cap having an axial groove receiving the cup-shaped opening of the tubular body, a dip stick fastened to the cap, a bayonet connection between the cap and the body allowing axial movement of the cap with respect to the body, the dip stick having a spring means around the upper portion thereof, the spring means contacting a radial projection member on the dip stick axially movable thereon, the radial projection adapted to contact the internal ledge on the body wherein the spring will force the cap away from the body to maintain the dip stick normally at a given level while depressing the cap towards the body will move the dip stick axially within the body to a measuring level, the spring cooperating with the bayonet lock to maintain the cap securely fastened to the body.

Unite 1 States atet [1 1 Jackson et a1.

[ DIP STICK [75] Inventors: Richard H. Jackson, Downers Grove; Harry B.Bak, Westchester, both of I11. [73] Assignee: Gits Bros. Mfg. Co., Inc.,Chicago,

Ill.

[22] Filed: Feb. 24, 1971 [21] Appl. No.: 118,284

[52] US. Cl. ..33/126.7 R [51] Int. (31. ..G01f 23/04 [58] Field ofSearch ..33/l26.7 R

[56] References Cited FOREIGN PATENTS OR APPLICATIONS 1,090,791 4/1955France ..33/l26.7 R 771,315 10/1934 France ..33/l26.7 R

Primary Examiner-Leonard Forman A dip stick assembly with a tubular bodyhaving an internal ledge of a fixed position and a cup-shaped externalopened end with a closure cap adapted to close the end, the closure caphaving an axial groove receiving the cup-shaped opening of the tubularbody, a dip stick fastened to the cap, a bayonet connection between thecap and the body allowing axial movement of the cap with respect to thebody, the dip stick having a spring means around the upper portionthereof, the spring means contacting a radial projection member on thedip stick axially movable thereon, the radial projection adapted tocontact the internal ledge on the body wherein the spring will force thecap away firom the body to maintain the dip stick normally at a givenlevel while depressing the cap towards the body will move the dip stickaxially within the body to a measuring level, the spring cooperatingwith the bayonet lock to maintain the cap securely fastened to the body.

Assistant xqmin rQha le Efibilms Attomey1-Iill, Sherman, Meroni, Gross &Simpson 44 A 45 3g rPn 11 1, 1, ,4 49

mp STICK BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates to dip sticks and more particularly to a dip stickhaving a spring means associated therewith for maintaining the stick ata given level, the stick being depressable to a measuring level.

2. Prior Art Dip sticks for measuring the lubricant level in an engine,transmission, or other type mechanism are old and common to the art. Ithas also been known to provide attached caps on the ends of such dipsticks, and to attach the caps to the engine or transmission housing ina removable but secured fashion.

However, such prior art dip sticks have had numerous disadvantages whenused in connection with high vibration engines such as jet aircraftengines and the like where extreme safety is required. Further, it isoftentimes extremely desirable to limit the amount of travel of the dipstick into the fluid compartment during operation of the respectiveengine or transmission so that it cannot become enmeshed with theworking components. However, it is desirable that the dip stick beinsertable to a deeper level for measuring. In order to obtain anaccurate reading, it is further desirable to provide a limitation on themaximum depth to which the dip stick can be inserted.

In other embodiments, especially in those embodiments where the stick isused in high-vibratory environment or in an environment where thelubricant may be under greaterthan atmospheric pressure, it is desirableto seal the dip stick entry point and to protect the major portion ofthe dip stick.

While various solutions to many of the above problem have been suggestedby some of the prior art examples, the prior art has not heretoforeachieved adequate solution of all of the problems in a design which issimple, economical to produce and safe to use.

SUMMARY OF THE INVENTION The present invention overcomes thedisadvantages of the prior art by providing a dip stick assembly havingthree major components, a housing attached body, a cap, and a dip stick.The housing attached body is tubular, having varying diameters toprovide a portion insertable within the housing, a'wider portionbottomed against the exterior of the housing for accurate positioning ofthe body and a cup-shaped open end exterior of the housing. An internalledge is provided at a given point along the length of the body withrespectto the end of the cup-shaped opened' end. The cap has an axialgroove thereinto from one end which receives the peripheral wall of thecup-shaped open end to provide a labyrinth path sealing against escapeof oil from the body portion. The inner diameter wall of the groove maycontain secondary seals and the outer diameter wall of the groove isequipped with bayonet slots matching with pins on the cup-shaped end ofthe body to firmly attached the cap to' the body in a detachable 'mannerwhile further allowing axial movement of the cap on the body. The axialmovement is limited by contact with the pins against the axial ends ofthe bayonet slot.

The dip stick is attached to the cap extending axially thereof and has aprojecting member positioned around it a spring interposed between thecap and the pro jecting member. When the cap is assembled on the body,the projecting member contacts the internal ledge compressing the springas the cap is moved axi- 5 ally of the body. Thereafter, revolution ofthe cap to align it with the bayonet slots and release of the axialpressure on the cap will allow the spring to force the cap away from thebody portion to thereby position the free end of the dip stick at adesired point in the working environment at a point removed from anypossible contact with the working parts.

Thereafter, depression of the cap to the extent allowed by the bayonetslots will move the dip stick to its measuring position within theworking environment.

It is therefore an object of this invention to provide a new andimproved dip stick assembly.

It is a more specific object of this invention to provide a dip stickassembly wherein the dip stick is maintained at a given level underspring influence and depressable to a measuring level.

It is a more specific object of this invention to provide a dip stickwherein the stick is maintained under spring influence at a given leveland depressable to a fixed point for measuring.

It is yet another and more specific object of this invention to providea dip stick assembly having a body portion with a cup-shaped open endattached to the housing in which the dip stick is to operate, the dipstick being attached to a cap adapted to be received over the cup-shapedend with the stick extending through the body, the cap having an axialgroove receiving the peripheral wall of the cup-shaped end, and the caphaving bayonet slots cooperating with pins on the cup-shaped end fordetermining the maximum penetration depth of the dip stick into theworking environment, spring means being provided to maintain the dipstick at a depth less than the maximum depth in the absence of unusualpressure against the cap.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantagesof the invention will be readily apparent from the following descriptionof certain preferred embodiments thereof, taken in conjunction with theaccompanying drawings, although variations and modifications may beeffected without departing from the spirit and scope of the novelconcepts of the disclosure, and in which:

FIG. 1 is a fragmentary cross-sectional view of the dip stick assemblyof this invention received in a hous- I FIG. 2 is a fragmentarycross-sectional view of the dip stick and cap portion of the assembly ofFIG. 1.

FIG. 3 is a side plan view of the cap of this invention. FIG. 4 is a topplan view of the cap of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The dip stick assembly 10 ofthis invention includes three major components, a body portion 11, a capassembly 12, and a dip stick assembly 13.

The body portion 11 is adapted to be inserted through the side wall 96of a housing 14 into the interior 15 thereof.

The body 11 is tubular, having a lower portion 17 terminating in anoutturned flange portion 18 with a groove 19 therearound. The housing 14may include an internal wall 14b having an opening 14c therein alignedwith the outside opening 99 in the outer wall 96. In such a case, theflange 18 will be dimensioned to be received in the opening 140 with anO-ring seal 19a in the groove 19 sealing the opening 14c except throughthe body 1 1. The lower end 20 is open. As illustrated at 21,approximately halfway up the body 11, the outer diameter increases toprovide a radially outwardly extending shoulder portion 22 terminatingin a cylindrical land 23 into which extends a radial groove 24 and anaxially spaced second groove 25. The side wall 26 of the groove remotefrom the shoulder 22 extends radially outwardly to a circumferentialland 27 terminating further radially outwardly than the land 23. Thecircumferential land 27 is axially narrow and provides a radial abutmentwall 28 on a plane with the wall 26 of the groove 25. Axially beyond theland 27, the body 11 is reduced in diameter exteriorly to provide asmaller diameter land 30. Thereafter, the outer diameter increases againat a ledge portion 31 to a full diameter portion 32 which is preferablywider than any other portion of the body 1 1 and which terminates in anopen end 33.

The inner diameter of the tubular body 11 varies, having its greatestdiameter 35 in the area of the in.- creased-diameter portion 32 at theopen end 33 extending axially inwardly to an internal ledge 36 formed bythe inner housing .wall of the ledge 31. The diameter is then reduced toan intermediate diameter portion 37 which extends from the innerdiameter ledge 36 to a second inner diameter ledge 39 which isillustrated as being positioned adjacent the groove 24 in the firstradially thickened portion 23 formed by the shoulder 22. The ledge 39may be spaced at other points along the body 11. Axially therebeyond thebody is reduced to its smallest diameter 40 which continues from theledge 39 to the open end 20.

In the preferred embodiment, the cap 12 is constructed of two concentricpieces, an outer diameter member 42 and an inner diameter member 43. Theinner diameter member is tubular and is H-shaped in cross section havinga peripheral circumferential wall 44 with an internal cross beam bridgemember 45 located intermediate the axial ends 46, 47 of the peripheralwall 44, and preferably spaced closer to the bottom end 47 than the topor outer end 46. A groove 48 extends circumferentially around theperipheral wall 44 on the exterior thereof closely spaced to the bottomend 47. The outer diameter of the peripheral wall 44 is dimensioned withrespect to the inner diameter of the cup-shaped open end 35 of the bodysuch that the inner member 43 can be received within the open end 33 ofthe body. A sea] member 49, preferably of the O-ring type, is receivedin the groove 48 and is adapted to contact the inner diameter 50 of thecupshaped portion 35 of the body in sealing relation therewith.

The outer portion 42 of the cap 12 has a substantially tubular portionterminating at one end, the upper end 56, in an in-turned flange 57.

The shape of the end 56 is as illustrated in FIG. 4 where outtumedportions 58 are provided to substantially square off the end of the capto allow gripping for ease of rotation of the cap.

The in-turned flange 57 extends inwardly into contact with the innerportion 43 of the cap at the end 46 thereof. The inner cap portion 43and the outer cap portion 42 may be splined or otherwise configured toprovide for a press-fit mate between the two to lock them together. atthe contact between the flange 57 and the outer diameter 59 of the end46 of the inner cap 43. Alternatively, they may be welded or in anyother way fixed together.

The provision of the in-turned flange 57 at the end 56 of the outer capprovides for a groove 60 between the inner cap piece 43 and the outercap portion 42 axially below the flange 57.

The inner diameter 61 of the tubular portion 55 of the outer cap member42 is dimensioned to be received around the exterior of the end portion32 of the body 11, in closed spaced relation thereto. Thus, thecupshaped end of the body extends upwardly into the groove 60 betweenthe inner and outer portions of the cap when the cap is placed over thebody. This presents a labyrinth path for escape of oil or vapors or foringress of foreign matter. Further, the seal 49 effectively preventssuch escape or ingress.

As best illustrated in FIG. 2, the tubular portion 55 of the outer capportion 42 extends axially beyond the end 47 of the inner portion andterminates at a free end 65.

As illustrated in FIG. 3, a pair of bayonet slots 66 are provided in thewall of the tubular portion 55. The slots have axially extending slotportions 67 which have their axial ends 68 and 69 enclosed within thematerial of the wall of the tubular portion 55. The bottom axial end 68tenninates in spaced relation to the bottom of the tubular portion. Anentrance slot 70 extends in at an angle from the end 65 of the tubularportion and is open to the slot 67 at the side thereof at approximatelythe end 69. Pins 71 are positioned on the exterior of the cup-shapedportion 35 of the body. The pins cooperate with the bayonet slots 66 toaffix the cap to the body in the normal manner whereby release of thecap requires depression of the capuntil the pins contact the end 69,then rotation of the cap coupled with axial movement to move the pinsthrough the angled slot 70.

The dip stick member 13 has a tubular end portion 80. The end 81 of thetubular portion is reduced in diameter providing a ledge 82. The portionof the end 81 from the ledge to the end is threaded and is receivedthrough an opening 83 in the bridge portion 45 of the inner cap portion43. A nut or the like 84 is received over the threaded end 81 andtightened down on the bridge to firmly affix the dip stick member 13 tothe bridge. The provision of the ledge 82 contacting with the portion ofthe bridge 45 around the opening 83 provides for enclampment of thebridge between the ledge 82 and the nut 84 to affix the dip stick member13 in a given position with respect to the cap whereby the space betweenthe bottom end 86 of the dip stick and the bridge 45 is pre-determinedand fixed.

Intermediate the ends 81, 86 of the dip stick member 13, the member maybe flattened out to provide a substantially rectangular portion having afiat face 90 on which measuring indicia 91' may be placed. The point offlattening between the tubular portion 80 and the flattened portion 90provides a ledge 92. A washer or radial projection member 92 having acentral opening 93 dimensioned to be received around the tubular portion80 abuts the ledge 91. Drainage openings 94 may be provided in thewasher. The washer 91 is free to slide along the tubular portion 80 anda coil spring or the like 95 is entrapped between the bridge 45 of theinner cap member 43 and the washer 92 urging the washer against theledge 91.

When the dip stick is received in the body 1 1 and the cap is receivedaround the cup-shaped end 35 of the body, the washer 92 will contact theinner ledge 39 of the body in abutting relation therewith. Further,axial movement of the cap and dip stick will compress the spring 95.Thus, when the cap is inserted around the pins 71 and rotated so thatthe pins are in the slots 67 of the bayonet slot, the compressed spring95 will push the cap away from the body until the pins 71 contact theend 68 of the bayonet slot. In this position, the depth of penetrationof the end 86 of the dip stick member 13 into the housing 14 isdetermined inasmuch as the spacing between the inner ledge 39 and thebridge 45 is determined due to the spring and the contact between thepins 71 and bayonet slot. 66. Further, because the dip stick is affixedto the bridge andis carried by the cap, any movement of the cap' willcause a movement of. the dip stick. Thus, depressing the cap until thepins 71 contact the end 69 of the bayonet slot will result in insertionof the dip stick 13 a given distance further into the housing 14. In theabsence of a force depressing the cap onto the body, the spring 95 willalways force the cap away from the body until contact between the pins71 and the end 68 of the bayonet slot 66. Thus, the dip stick isnormally held a given depth into the housing 14, which depth is'normallychosen to be sufficiently spaced from operating. portions of, themachinery so as to prevent contact therewith. When it is desired to takea measure of the oil in the housing 14, the cap is depressed untilcontact between the pins 71 and the end 69 of the bayonet slot preventsfurther depression. This will move the dip stick to a measuring depthgreater than its normal depth.

The spacing ofthe body 11 into the housing 14 is predetermined bycontact between the outer flange 27 of the body and the wall 96 of thehousing 14. O-ring seals 97 received in the grooves 24, 25 andcontacting the peripheral wall 98 of the opening 99 of the housing 14through which the body 11 is received effectively seal the body 11housing 14 opening. The housing 14 may be configured to allow the body11 to be fastened thereto as by a snap ring 100.

It will therefore be appreciated that the depth of penetration of thedipstick is at all times controlled, first by the fixed depthpenetration of the body due to the contact between the ledge 27 and thesurface 96 of the housing wall, secondarily between the fixedpositioning of the dip stick to the bridge 45, thirdly due to themaximum-minimum positioning of the cap 12 with respect to the body 11caused by the bayonet slots 66 and the pins 71 and fourthly, by theaction of the spring 95 which tends to maintain a dip stick penetrationat the minimum by always urging the pins 71 into contact with the loweraxial end 68 of the bayonet slot.

Although we have herein set forth our invention with respect to certainspecific principles and details thereof, it will be understood thatthese may be varied without departing from the spirit and scope of theinvention as set forth in the hereunto appended claims.

We claim as our invention:

1. A dip stick assembly comprising: a body portion; said body portionincluding an elongated tube of axially varying diameter having an inletend, said inlet end having a circumferential peripheral wall and an openend formed by said wall, a cap portion, said cap portion substantiallycup-shaped having a peripheral circumferential wall with an open enddefined by portions of said wall, an annular axially extending groove inthe cap peripheral wall extending from the open end, said groovedimensioned to receive portions of the circumferential peripheral wallof the inlet end, a dip stick fixedly attached to said cap dependingtherefrom and projecting from the open end and dimensioned to extendthrough the body portion when the cap is received around the inlet endperipheral wall of the body portion, and seal means in the grooveengaging the inlet and peripheral wall, said body portion has aninternal ledge intermediate the ends thereof and the said sip stick hasa radial abutment member slidably received therearound and freed foraxial movement over at least a portion of the said axial length of thedip stick, the said radial abutment member having an outer diametergreater than the inner diameter of the said internal ledge of the saidbody portion, and a spring means around the said dip stick entrappedbetween a portion of the said cap and the said radial abutment urgingthe said radial abutment away from the said cap whereby when the saidradial abutment is abutted against the said internal ledge of the saidbody, the said spring urges the said cap away from the said body, anaxially extending slot and pin assembly, one of said slot and pinassembly being located on said cap and the other of said slot and pinassembly being located on said body, said pin being slidable in saidslot to guide the raising and lowering of said cap and dipstick relativeto said body,'and means on said cap for locking said pin in said slot inan elevated position.

2. The assembly of claim 1 wherein the locking means includes a bayonetslot including a locking slot and pin assembly between the said inletend peripheral wall and the said cap, the locking slot of the saidbayonet slot extending axially whereby axial movement of the said capwith respect to the said body is limited by the said bayonet slot andpin assembly.

3. The assembly of claim 2 wherein the said body has an externalradially projecting ledge intermediate the ends thereof, the said ledgeadapted to abut the periphery of a housing opening into which the saidbody is received to dimension the said body at a specified point withrespect to the said housing openmg.

4. The assembly of claim 2 wherein the said dip stick has a radialabutment thereon limiting movement of the said radially projectingmember.

5. The assembly of claim 4 wherein the said axially extending groove ofthe said cap is formed between an outer circumferential wall member ofthe said cap and an inner circumferential wall member of the said cap,the two wall members attached together at one end of the said cap andspaced radially apart from one another 7 remote from the said one end todefine the said groove,

member and the said pins are affixed to portions of the outer peripheryof the inlet end of the said body member.

1. A dip stick assembly comprising: a body portion; said body portionincluding an elongated tube of axially varying diameter having an inletend, said inlet end having a circumferential peripheral wall and an openend formed by said wall, a cap portion, said cap portion substantiallycup-shaped having a peripheral circumferential wall with an open enddefined by portions of said wall, an annular axially extending groove inthe cap peripheral wall extending from the open end, said groovedimensioned to receive portions of the circumferential peripheral wallof the inlet end, a dip stick fixedly attached to said cap dependingtherefrom and projecting from the open end and dimensioned to extendthrough the body portion when the cap is received around the inlet endperipheral wall of the body portion, and seal means in the grooveengaging the inlet and peripheral wall, said body portion has aninternal ledge intermediate the ends thereof and the said sip stick hasa radial abutment member slidably received therearound and freed foraxial movement over at least a portion of the said axial length of thedip stick, the said radial abutment member having an outer diametergreater than the inner diameter of the said internal ledge of the saidbody portion, and a spring means around the said dip stick entrappedbetween a portion of the said cap and the said radial abutment urgingthe said radial abutment away from the said cap whereby when the saidradial abutment is abutted against the said internal ledge of the saidbody, the said spring urges the said cap away from the said body, anaxially extending slot and pin assembly, one of said slot and pinassembly being located on said cap and the other of said slot and pinassembly being located on said body, said pin being slidable in saidslot to guide the raising and lowering of said cap and dipstick relativeto said body, and means on said cap for locking said pin in said slot inan elevated position.
 2. The assembly of claim 1 wherein the lockingmeans includes a bayonEt slot including a locking slot and pin assemblybetween the said inlet end peripheral wall and the said cap, the lockingslot of the said bayonet slot extending axially whereby axial movementof the said cap with respect to the said body is limited by the saidbayonet slot and pin assembly.
 3. The assembly of claim 2 wherein thesaid body has an external radially projecting ledge intermediate theends thereof, the said ledge adapted to abut the periphery of a housingopening into which the said body is received to dimension the said bodyat a specified point with respect to the said housing opening.
 4. Theassembly of claim 2 wherein the said dip stick has a radial abutmentthereon limiting movement of the said radially projecting member.
 5. Theassembly of claim 4 wherein the said axially extending groove of thesaid cap is formed between an outer circumferential wall member of thesaid cap and an inner circumferential wall member of the said cap, thetwo wall members attached together at one end of the said cap and spacedradially apart from one another remote from the said one end to definethe said groove, the said inner member being axially shorter than thesaid outer member.
 6. The assembly of claim 5 wherein the said bayonetslot is defined by portions of the said outer wall member and the saidpins are affixed to portions of the outer periphery of the inlet end ofthe said body member.